Convert Apple IIc to usb

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Daniel Beardsmore

31 Jan 2014, 23:00

option8 wrote:The II and II+ use an ASCII keyboard instead of a matrix …
What do you mean by this, exactly?

option8

31 Jan 2014, 23:07

that is to say, the keyboard includes the matrix decoder on-board, so what it sends to the logic board is ASCII keystrokes. later models (Apple IIe and on) had the decoder/keyboard ROM on the logic board, so the keyboard was just the matrix of switches, and it was decoded on the logic board.

i'm probably not explaining it that well...

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bhtooefr

01 Feb 2014, 00:00

][ and ][+: Matrix -> Encoder board outputting parallel strobed ASCII -> Motherboard
//e, //c: Matrix -> Motherboard

TheDoctor

01 Feb 2014, 13:26

Sorry, I misread your earlier post.

I will post you a Lisa KB when I have the time. Please PM your address to me.
I will be ordering the kit soon, and would like to discuss some other things with you later.

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Daniel Beardsmore

05 Feb 2014, 02:43

option8 wrote:that is to say, the keyboard includes the matrix decoder on-board, so what it sends to the logic board is ASCII keystrokes.
In other words, it's whether the custom PCB needs to translate scancodes, or scan the matrix?

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bhtooefr

05 Feb 2014, 03:38

Although "scancodes" is a bit fancy, here - it's outputting raw ASCII characters. And the modifiers don't get exposed - Ctrl is simply XOR 0x40 on the character generated, and Shift is basically selecting a second layer in the controller IIRC.

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Daniel Beardsmore

09 Feb 2014, 04:01

What's your best guess as to the weight of Alps SKCM Amber? I've just got three, and they're quite heavy.

I figured 20–30% heavier than regular Alps switches, so that's 85 gf at least, and my hilariously awful experiment gives me something like 80–100 gf, which is where I was guessing.

I can't imagine wanting to type on that, but I don't know if I just have some very worn switches — one of them doesn't even actuate any more, though I could have broken it when I was cleaning it for photography (the actuator leaf doesn't quite close the contacts when the slider is depressed).

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